That same [report] on South Korea did suggest that certain relatively medium-term improvements might be sustainable; the numbers and proportions of immigrants and immigrant descended people necessary to sustain either the peak population of South Korea or the peak working-age population of South Korea seems possible. South Korea is more open to immigration than neighbouring Japan, at least, and the movement of people from Vietnam, China, and the Philippines associated with marriage-driven immigration could contain the seeds for a broader migratory movement. South Korea might come to emulate a Canada that is enacting something very much like those policies right now, you could say. For those policies to work, though, you need a labour force that is permeable to people of diverse backgrounds at every level.

Dealing with more immigration poses its own set of challenges. There is also the prospect of encouraging more births and sparking a baby boom. All the policies on the table are easier said than done. I think we are approaching the challenges with the wrong framework.

We are using an industrial mindset to deal with a knowledge economy. Population growth equals economic growth. In a knowledge economy, quality (e.g. educational attainment of workforce) trumps quantity. This is the way forward emerging from the ravaged Rust Belt. Even there, struggling cities are slow to catch on to the Pittsburgh Paradigm.

Economic growth, as a friend pointed out to me succinctly, is the product of growth in productivity and in labour force. One factor can compensate for another to a limited extent, sure, but they can't do so indefnitely: sooner or later there will be bottlenecks.

I'm not inclined to bet on the extent to which roboticization could substitute for a contracting human labour force, say. The redistribution of labour force from one sector to another can likewise play a critical role, and have--as you've documented--been successful in some areas. How long will they remain successful, though, and what about the areas where they won't work?